Traumatic brain injury (TBI) results in cognitive impairment, which can be long-lasting after moderate to severe TBI. Currently, there are no FDA-approved therapeutics to treat the devastating consequences of TBI and improve recovery. A wealth of experimental evidence shows that mitochondrial dysfunction is poised to be a pivotal link in the neuropathology of brain injury. We previously have targeted bioenergetic impairment with mitochondria-directed therapeutics, including mild mitochondrial uncouplers, which have shown to be neuroprotective. These uncouplers facilitate the movement of protons from the mitochondrial inner-membrane space into the mitochondrial matrix, thereby reducing the mitochondrial membrane potential (??). While complete uncoupling of mitochondria would be detrimental, we have published data showing that transient or ?mild uncoupling? confers neuroprotection in preclinical models of TBI. Recently, we demonstrated that a prodrug of 2,4-dinitrophenol (DNP), MP201, a mitochondrial uncoupler with better pharmacodynamic properties including higher tolerability and extended elimination time, rescues acute mitochondrial bioenergetics, reduces oxidative damage, increases brain-derived neurotropic factor (BDNF) and is neuroprotective. We hypothesize that the optimal dosage and timing of therapeutic intervention of MP201 is neuroprotective across species following focal contusion brain injury. Our proposed studies will explore how MP201 administration can improve acute, longitudinal, and chronic outcomes, paired with critical biomarkers, including platelet physiology and neurochemical profiles. To achieve this, we will use innovative techniques across multiple institutions to assess synaptic and non-synaptic mitochondria in both porcine and murine models of TBI. Additionally, we will extend our findings to examine therapeutic efficacy, measuring longitudinal cortical morphology (T2/DTI scanning), neurometabolite profiles (MRS scanning), platelet signature (as a novel biomarker and biosensor), and cognitive behavior. Finally, we will explore the underlying mechanism behind the long-term neuroprotection imparted by MP201 after TBI, examining BDNF levels and mitochondrial restoration. With strong preliminary data and utilizing many innovative and clinically-relevant techniques, we anticipate this proposal will generate ground-breaking data. Overall, this proposal will highlight highly translatable therapy by MP201 to alleviate negative outcomes of TBI.